The present invention relates generally to piering systems for raising and supporting building foundations and the like, and more particularly to a lifting assembly comprising a removable and reusable lifting bracket and a support bracket for raising and supporting a load.
Many types of building structures are supported by foundations that in turn are supported by soil rather than by more stable bedrock or other supporting strata. Shifting of the supporting soil over time can cause the foundation to sink, which can lead to various problems including structural damage. Unless the foundation is supported, further shifting can occur and worsen the structural damage. Furthermore, it is frequently desirable to raise the foundation to its original level in order to facilitate restoration of the structure to a proper condition.
In foundation piering systems, the foundation of a structure is excavated down to the footings at each pier location, pilings are driven into the ground through unstable soils to rock or load bearing strata by hydraulic rams for lifting and stabilizing the foundation and preventing future settlement. A support bracket is attached to the foundation footings from below and raised by hydraulic rams for vertical adjustment of the foundation.
Many devices and methods have been developed for raising and supporting a foundation. Many such devices and methods employ piers that are driven into the ground adjacent an edge of the foundation until the piers encounter bedrock or other relatively firm supporting strata. Jacking devices are used for jacking up the edge of the foundation, using the piers for support. When the foundation is raised to the desired level, the foundation is affixed to the piers and the jacking equipment is removed.
In some such lifting devices, brackets are affixed to the foundation and are slidably engaged with the piers, and the jacking devices engage the brackets for raising the foundation. A bracket typically includes a pier-receiving portion such as a collar or sleeve that surrounds the pier in close-fitting fashion, and a support plate rigidly affixed to the pier-receiving portion and configured to engage a lower surface of a foundation. The pier-receiving portion is sized to fit closely about the pier so that the bracket is able to slide upward and downward along the pier but is substantially prevented from moving in any other direction.
U.S. Pat. No. 6,142,710 to Holland Jr. discloses a lifting assembly for raising and supporting an edge of a foundation that includes a lifting saddle slidably received over a pier that is driven into the ground adjacent the edge of the foundation, a bracket supported by the lifting saddle and adapted to be affixed to and to support the foundation, and a jacking apparatus configured to be supported atop an upper end of the pier. The lifting saddle is connected to the jacking apparatus by threaded rods slidably received through the jacking apparatus. The bracket is pivotally connected to the lifting saddle such that the bracket can rock side-to-side, thus self-aligning and remaining aligned with the foundation during a lifting operation. The bracket can also pivot about a vertical axis and can slide in a forward or rearward direction relative to the lifting saddle. The lifting saddle can pivot relative to the pier about a horizontal axis.
The prior art discloses lifting assemblies including a support bracket and a lifting bracket that are attached to a jacking apparatus for lifting a supporting a foundation. The support bracket and lifting bracket are fixed components of a piering system that are not removable or reusable. The present invention provides a lifting bracket that is removable from the support bracket, piering pole and jacking apparatus and can be reused on other lifting assemblies.